In article <b5215baacd93a6e85efc59947f9b8ed9.squirrel@xxxxxxxxxxxxxxxxxxxxxxx>,
<m.roth@xxxxxxxxx> wrote:
> Warren Young wrote:
> > On Oct 25, 2017, at 10:02 AM, Mark Haney <mark.haney@xxxxxxxxxxx> wrote:
> >>
> >> I have a file with two columns 'email' and 'total' like this:
> >>
> >> me@xxxxxxxxxxx 20
> >> me@xxxxxxxxxxx 40
> >> you@xxxxxxxxxx 100
> >> you@xxxxxxxxxx 30
> >>
> >> I need to get the total number of messages for each email address.
> >
> > This screams out for associative arrays. (Also called hashes,
> > dictionaries, maps, etc.)
> >
> > That does limit you to CentOS 7+, or maybe 6+, as I recall. CentOS 5 is
> > definitely out, as that ships Bash 3, which lacks this feature.
> <snip>
> Associative arrays?
>
> Awk! Awk! (No, I am not a seagull...)
>
> sort file | awk '{ array[$1] += $2;} END { for (i in array) { print i "\t"
> array[i];}'
Why the sort? It doesn't matter in what order the lines are read.
Wouldn't this give you the same?
awk '{ array[$1] += $2;} END { for (i in array) { print i "\t" array[i];}}' <file
Cheers
Tony
--
Tony Mountifield
Work: tony@xxxxxxxxxxxxx - http://www.softins.co.uk
Play: tony@xxxxxxxxxxxxxxx - http://tony.mountifield.org
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